From e3abe8bf7f49c38e952917dd347398b706c21cac Mon Sep 17 00:00:00 2001
From: tomoya <Tomoya.Fujita@sony.com>
Date: Thu, 28 May 2020 07:06:50 +0900
Subject: [PATCH] Fix lock-order-inversion (potential deadlock) (#1135)

Signed-off-by: Tomoya.Fujita <Tomoya.Fujita@sony.com>
---
 rclcpp/src/rclcpp/node_interfaces/node_graph.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/rclcpp/src/rclcpp/node_interfaces/node_graph.cpp b/rclcpp/src/rclcpp/node_interfaces/node_graph.cpp
index 0aa361e..4d0d46e 100644
--- a/rclcpp/src/rclcpp/node_interfaces/node_graph.cpp
+++ b/rclcpp/src/rclcpp/node_interfaces/node_graph.cpp
@@ -368,9 +368,11 @@ rclcpp::Event::SharedPtr
 NodeGraph::get_graph_event()
 {
   auto event = rclcpp::Event::make_shared();
-  std::lock_guard<std::mutex> graph_changed_lock(graph_mutex_);
-  graph_events_.push_back(event);
-  graph_users_count_++;
+  {
+    std::lock_guard<std::mutex> graph_changed_lock(graph_mutex_);
+    graph_events_.push_back(event);
+    graph_users_count_++;
+  }
   // on first call, add node to graph_listener_
   if (should_add_to_graph_listener_.exchange(false)) {
     graph_listener_->add_node(this);